Relationship between downwelling surface shortwave radiative fluxes and sea surface temperature over the tropical Pacific: AMIP II models versus satellite estimates

Incident shortwave radiation at the Earth's surface is the driving force of the climate system. Understanding the relationship between this forcing and the sea surface temperature, in particular, over the tropical Pacific Ocean is a topic of great interest because of possible climatic implications. The objective of this study is to investigate the relationship between downwelling shortwave radiative fluxes and sea surface temperature by using available data on radiative fluxes. We assess first the shortwave radiation from three General Circulation Models that participated in the second phase of the Atmospheric Model Intercomparison Project (AMIP II) against estimates of such fluxes from satellites. The shortwave radiation estimated from the satellite is based on observations from the International Satellite Cloud Climatology Project D1 data and the University of Maryland Shortwave Radiation Budget model (UMD/SRB). Model and satellite estimates of surface radiative fluxes are found to be in best agreement in the central equatorial Pacific, according to mean climatology and spatial correlations. We apply a Canonical Correlation Analysis to determine the interrelated areas where shortwave fluxes and sea surface temperature are most sensitive to climate forcing. Model simulations and satellite estimates of shortwave fluxes both capture well the interannual signal of El Niño-like variability. The tendency for an increase in shortwave radiation from the UMD/SRB model is not captured by the AMIP II models

Current Efficiency, Dielectric Measurements & Ion Mobility Studies of Anodic Oxide Films Formed on Tantalum in Aqueous Electrolytes

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Simulations of Oscillation Modes of the Solar Convection Zone

We use the three-dimensional hydrodynamic code of Stein and Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar oscillations. Our first result is that the properties of oscillation modes in the simulation closely match the observed properties. Recent observations from SOHO/MDI and GONG have confirmed the asymmetry of solar oscillation line profiles, initially discovered by Duvall et al. In this paper we compare the line profiles in the power spectra of the Doppler velocity and continuum intensity oscillations from the SOHO/MDI observations with the simulation. We also compare the phase differences between the velocity and intensity data. We have found that the simulated line profiles are asymmetric and have the same asymmetry reversal between velocity and intensity as observed. The phase difference between the velocity and intensity signals is negative at low frequencies and jumps in the vicinity of modes as is also observed. Thus, our numerical model reproduces the basic observed properties of solar oscillations, and allows us to study the physical properties which are not observed.Comment: Accepted for publication in ApJ Letter

Studies in Sulphonamides Part XIII: Synthesis of Some new 1-methyl-3-aryl-2-(arylazo/N-substituted p-sulphamylbenzeneazo) propane-1, 3-diones as potential antibacterials

Two 1-methyl-3-arylpropane-1,3-diones viz., 1-methyl-3(2',4'-dimethoxyphenyl)-and l-methlyl-3(3',4'-dimethoxyphenyl) propane-1,3-diones have been synthesised and coupled with diazotised simple and sulphonamide bases in presence of sodium acetate to furnish the corresponding 1-methyl-3(2',4'-3',4'-dimethoxyphenyl)-2 (arylazo/N-substituted p-sulphamylbenzeneazo)propane-1,3-diones. All these compounds were later subjected to in vitro screening against S. aureus, E. coli and p.pyocyanea when these showed considerable activity

Studies in Heterocyclic Compounds-Part XXXIII : Synthesis and in vitro screening of some 1,3-diaryl-5-(arylazo/N-substituted p-sulphamylbenzeneazo) dihydro-2-thioxo-4,6 (1H, 5H)-pyrimidinedioes

1-Phenyl-3-(p-methoxyphenyl)- and 1,3-di(p-methoxyphenyl) dihydro-2-thioxo-4,6 (1H, 5H)-pyrimidinediones have been synthesised and coupled with different diazotised simple and sulphonamide bases to furnish the corresponding 5-(arylazo/N- substituted p-sulphamylbenezeneazo)dihydro-2-thioxo-4, 6(1H, 5H)-pyrimidinediones. On in vitro screening these were found to exhibit considerable activity against a number of micro-organisms

Chemical control of balsam wooly aphid (Homoptera: Adelgidae) on seedlings of Abies amabilis

Assessment was made of the effectiveness of four insecticides for eradicating <i>Adelges piceae</i> (Ratz.) from Abies seedlings. Seedlings with overwintering immature aphids were top dipped in the insecticides in fall or spring (before or after cold storage), while those with mature, egg-laying aphids were treated in spring. The overwintering immature aphids were completely killed by all of the insecticides and it was recommended that any one of the following treatments would provide sanitation of <i>Abies</i> from aphid during this stage: 1.0% propoxur suspension; 2.0% carbaryl suspension: 2.0% Insecticidal Soap solution; 0.5% permethrin emulsion. Treatment of mature aphids was less effective due to relative tolerance of bwa eggs and it was recommended that treatment during this stage of the aphid be avoided

Critical exponents and the correlation length in the charge exchange manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3}

The critical regime of the charge exchange (CE) manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3} is investigated using linear and non linear magnetic susceptibility and the divergence of the third ordered susceptibility (chi{_3}) signifying the onset of a conventional freezing transition is experimentally demonstrated. The divergence in chi{_3}, dynamical scaling of the linear susceptibility and relevant scaling equations are used to determine the critical exponents associated with this freezing transition, the values of which match well with the 3D Ising universality class. Magnetic field dependence of the spin glass response function is used to estimate the spin correlation length which is seen to be larger than the charge/orbital correlation length reported in this system.Comment: 4 pages, 4 Figure